One motor each side, at the top, between the inner and outer wiper seals. One shaft runs from each motor top to bottom, with 2 drive gears, one from upper track and one for lower. Motor is held in place by one small screw. Wires usually run from the bottom up to the motor. There are a few videos showing the removal of the motor, or disengaging it to allow manual movement of the slide.
John and Rebecca Dickson
Emma-7 / Little John-5 / Iva-1
Full Timing Again, Rev B
2013 Ford F-350 Lariat CC LB PSD
2015 SOB TT - With OC's Awning Poles (#8)
At least in Heaven, RVs will be perfect, and I won't have to keep fixing them.